re. want to verify mech boost gauge readings...

[Swann, Benjamin R. (BSWANN)]

[finally got a vdo boost gauge hitched up. i wanted to bounce what it's 
telling me off the list to see if i hooked it up right. i tee'd it into the 
vac line that goes from the back of the manifold to behind the pass side 
fender. i used the decel valve line @ the metal tee NEXT TO the send line 
for the ecu (mechanic told me to not use the ecu line as he claimed it could

screw up the ecu signal).

the gauge reads 12-14 in. vaccum @ idle and max boost (that it makes right 
now) is 1.2 bar on the dash = 5/6 psi on the vdo. at decel from full boost 
it'll drop to -20ish "vac. is that right / in the ballpark?

i feel like it's rreading right. it makes sense that the engine is sucking 
at idle. i ask bc my mechanic said it should read "0" at idle and boost/vac 
from there.

is he nuts? or am i?
Thanx!

jim "gauges dont lie" rose]

I think your mechanic is wrong on both accounts.

You can tee in at the back of the ECU - that is what is being measured.

You should be pulling vacuem at idle - around 18 at idle up to 30 when
seriously downshifting.

Regards,

Ben